Aplicações biotecnológicas do fungo ligninolítico pleurotus pulmonarius (FR.) quél

• Autor(a) principal: Silva, Bruna Polacchine da
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Estadual de Maringá (RI-UEM)
• Texto Completo: http://repositorio.uem.br:8080/jspui/handle/1/1866
• topic: Pleurotus pulmonarius; Enzimas ligninolíticas; Manganês peroxidase; Pleurotus pulmonarius; Antimicrobiano; Antifúngico; Antibacteriano; Pleurotus pulmonarius; Medicinal mushroom (Fungo medicinal); Pleurotus pulmonarius (Basidiomicetos); Fungos da podridão branca; Brasil.; Pleurotus pulmonarius; White-rot fungi; Manganese peroxidase; Antimicrobial activity; Antifungal activity; Brazil.; Ciências Biológicas; Bioquímica

Basidiomycetes and Ascomycetes play a crucial role in the balance of ecosystems. They are the major decomposers of lignocellulosic material in several ecosystems and play an essential role in the cycling of carbon and other nutrients. There are about 10,000 species of white rot fungi, with varying capacities to degrade lignin, cellulose and hemicellulose. However, only a few dozen have been properly studied. Most commonly studied species of white rot fungi are subdivided into six families: Phanerochaetaceae (Phanerochaete chrysosporium), Poliporaceae (Trametes versicolor and Pycnoporus sanguineus), Marasmiaceae (Lentinula edodes), Pleurotaceae (oyster mushrooms such as Pleurotus ostreatus and Pleurotus pulmonarius) Hymenochaetaceae (Inonotus hispidus and Phellinus igniarius) Ganodermataceae (Ganoderma lucidum and Ganoderma applanatum) and Meruliaceae (Bjerkandera adusta, Irpex iacteus and Phlebia radiate). The objective of the first article was to purify and characterize the enzyme manganese peroxidase (MnP) of Pleurotus pulmonarius and evaluate its capability to decolorize synthetic dyes. P. pulmonarius was cultured for 14 days under solid state conditions using pineapple wastes as substrate. Under this condition, MnP was the main ligninolytic enzyme found in the culture filtrates. The enzyme was purified to apparent electrophoretic homogeneity through acetone precipitation and gel filtration using Sephadex G-100 column. The main results were: MnP was purified 12.1-folds with a yield of 28.4% and a specific activity of 135.52 U/mg proteins. The 42 KDa-monomeric proteins were active over a large range of pH (4.0 - 6.0) and at a temperature of 50°C. The enzyme was stable at temperatures up to 40°C. At -20°C the enzyme was stable for at least 6 months. The KM values for Mn+2 and H2O2 at pH 4.5 and 40°C were 19.2 and 16,8 µM, respectively. The enzyme was strictly dependent of Mn+2 for oxidizing phenolic and non-phenolic compounds. It showed high activity and stability in the presence of organic solvents such as acetone, ethanol, acetonitrile and isopropanol, and was able to decolorize the anthraquinonic dye Remazol Brilliant Blue R and the azo dye Congo red in the presence of 1M Na2SO4 and NaCl. The properties presented by P. pulmonarius manganese peroxidase certainly make this enzyme a good agent for textile dye effluents treatment. The objectives of the second article was to evaluate the antimicrobial activities of mycelial extracts of Pleurotus pulmonarius obtained in submerged cultures using glucose, starch and cassava bagasse as carbon source. The highest antimicrobial activities were obtained after 6 days of cultivation using glucose and starch as carbon source. Despite the efforts, it was not possible to identify how molecules are responsible for antimicrobial activity of P. pulmonarius mycelia extracts.